Proximity regulation system for use with a portable cell phone and a method of operation thereof

ABSTRACT

Proximity regulation systems for use with a portable cell phone, a portable cell phone and a method of operating the same. In one embodiment, the proximity regulation system includes a location sensing subsystem configured to determine a location of a portable cell phone proximate a user by determining a mode of operation of the portable cell phone. A power governing subsystem is coupled to the location sensing subsystem and configured to determine a proximity transmit power level of the portable cell phone based on the location.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/967,140, entitled “A PROXIMITY REGULATION SYSTEM FOR USE WITH APORTABLE CELL PHONE AND A METHOD OF OPERATION THEREOF”, filed on Sep.28, 2001, by Richard L. McDowell, et al., which is currently pending.The above-listed application is commonly assigned with the presentinvention and is incorporated herein by reference as if reproducedherein in its entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention is directed, in general, to a mobiletelecommunications device and, more specifically, to a system and methodof determining a proximity transmit power level of a portable cell phonebased on a proximity to a user.

BACKGROUND OF THE INVENTION

Since the inception of the wireless or cellular (“cell”) phone in thelate 1940's, cell phone usage has expanded beyond their utilitarianbeginnings. Presently, cell phones are being used in every aspect ofbusiness along with every facet of personal life. People of all ages arenow using cell phones as the price of cell phones and services decrease.Presently, more than 74 million cell phones are in use in the UnitedStates with estimates predicting more than 139 million in a few years.Cell phones are moving beyond communication tools, and are now taking aplace in history by weaving themselves into the social fabric bybecoming fashion statements and symbols of power and importance.

Along with the increase in usage has come the requests for improvedservice and communication quality. Consumers are now looking for morethan just wireless voice communication but also Internet access,calendars, organizers, and even games. Meanwhile, manufacturers struggleto meet consumer demands for more options and better quality of service.

Typically, the quality of service of a cell phone is proportional to thetransmit power level of the cell phone. Though no definite proof hasbeen determined, health concerns have arisen due to the power used totransmit the radio frequency of cell phones when operated close to thebody of a cell phone user. For example, when held close to the ear, manyusers have health concerns about the high levels of radio frequencyenergy causing damage to brain cells.

Most of the concerns from consumers center around using the cell phoneclose to the ear or head of a user. New studies, however, have alsosuggested that cell phone usage may possibly cause stomach cancer whenlocated near the midsection when sending and receiving data textmessaging. Cell phone users still want the best possible quality ofservice from their cell phone. However, health concerns regarding thetransmit power of cell phones are now beginning to affect some users.

Manufacturers have tried several options to relieve the fears ofconsumers. One such option involves permanently reducing the power ofthe transmitter in cell phones. Though this may be perceived as a safetyadvantage to some customers, unfortunately, this also reduces thequality of service of the cell phone. Another option for consumers isthe use of cell phones with a base that typically allows a highertransmit power level of up to three watts. This may be the case for acell phone that is permanently mounted, such as in an automobile. Thesetype of cell phones, however, do not allow the flexibility demanded byconsumers that is found in the use of a portable cell phone.

Accordingly, what is needed in the art is a system and method toautomatically reduce the transmit power level of a portable cell phonewhen located near a human body thereby decreasing the perception ofhealth risks associated with the use thereof.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, thepresent invention provides a proximity regulation system for use with aportable cell phone. In one embodiment, the proximity regulation systemincludes: (1) a location sensing subsystem that is configured todetermine a location of the portable cell phone proximate a user bydetermining a mode of operation of the portable cell phone and (2) apower governing subsystem is coupled to the location sensing subsystemand configured to determine a proximity transmit power level of theportable cell phone based on the location.

In another aspect, the present invention provides a method of operatinga portable cell phone including: (1) determining a location of theportable cell phone proximate a user based on a mode of operation of theportable cell phone, (2) providing a control signal based on thelocation and (3) determining a proximity transmit power level of theportable cell phone based on the control signal.

In yet another aspect, the present invention provides a portable cellphone that includes: (1) an operation mode input or circuit and (2)means for determining a transmit power level of the portable cell phonebased on the operation mode input or circuit.

In still another aspect, the present invention provides a proximityregulation system for use with a portable cell phone, including a powergoverning subsystem configured to determine a transmit power level ofthe portable cell phone based on a mode of operation thereof.

Additionally, the present invention provides a proximity regulationsystem for use with a portable cell phone including means fordetermining a transmit power level of the portable cell phone based on amode of operation thereof.

The foregoing has outlined, rather broadly, preferred and alternativefeatures of the present invention so that those skilled in the art maybetter understand the detailed description of the invention thatfollows. Additional features of the invention will be describedhereinafter that form the subject of the claims of the invention. Thoseskilled in the art should appreciate that they can readily use thedisclosed conception and specific embodiment as a basis for designing ormodifying other structures for carrying out the same purposes of thepresent invention. Those skilled in the art should also realize thatsuch equivalent constructions do not depart from the spirit and scope ofthe invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a network diagram of an embodiment of a cellulartelephone network employing a portable cell phone constructed inaccordance with the principles of the present invention;

FIG. 2 illustrates a block diagram of an embodiment of a portable cellphone employing a proximity regulation system constructed in accordancewith the principles of the present invention; and

FIG. 3 illustrates a flow diagram of an embodiment of a method ofoperating a portable cell phone constructed in accordance with theprinciples of the present invention.

DETAILED DESCRIPTION

Referring initially to FIG. 1, illustrated is a network diagram of anembodiment of a cellular telephone network, generally designated 100,employing a portable cell phone 120 constructed in accordance with theprinciples of the present invention. The cellular telephone network 100includes a communications tower 110 in communication with the portablecell phone 120, employable by a portable cell phone user 150. Theportable cell phone 120 includes an antenna 125, a power circuit 130 anda proximity regulation system 140.

The communications tower 110 is a conventional communications tower thatis positioned to communicate with the portable cell phone 120. Thecommunications tower 110 may provide either analog or digitalcommunications depending on the cellular telephone network 100 beingused. For more information regarding communications towers and their usein cellular telephone networks, see “Mobile Communications Engineering:Theory and Applications” by William C. Y. Lee, McGraw Hill (1997), whichis incorporated herein by reference.

In the illustrated embodiment, the portable cell phone 120 is a digitalcell phone capable of receiving both voice and text messaging. In analternative embodiment, the portable cell phone 120 may also be capableof using a headset attachment to allow hands-free operation. Theportable cell phone 120 may also attach to a belt clip for storage orfor use in conjunction with a headset attachment. In addition, theportable cell phone 120 may also allow hands-free operation while storedin a cradle. The cradle may be a conventional cradle, which isconstructed to hold or store the portable cell phone 120.

The antenna 125 is a conventional portable cell phone antenna thatprovides communications between the portable cell phone 120 and thecommunications tower 110. Through the antenna 125, the portable cellphone 120 sends and receives voice or data communications across thecellular telephone network 100 via the communications tower 110.

In the illustrated embodiment, the power circuit 130 may be a typicalpower circuit in the portable cell phone 120 that produces a transmitpower level equivalent to, for instance, a maximum transmit power levelof one watt. Through communications with the communications tower 110employing the antenna 125, the power circuit 130 may also provide anetwork adjusted transmit power level that is lower than the maximumtransmit power level of one watt. The network adjusted transmit powerlevel is based on a transmit signal strength of a communications pathbetween the communications tower 110 and the portable cell phone 120.

In an advantageous embodiment of the present invention, the powercircuit 130 is further coupled to the proximity regulation system 140that determines a proximity transmit power level of the portable cellphone 120 based on its location proximate the portable cell phone user150. Though not illustrated in FIG. 1, the proximity regulation system140 includes a location sensing subsystem and a power governingsubsystem, which cooperate to determine both the proximity transmitpower level and when it may be employed. Both the location sensingsubsystem and the power governing subsystem are more fully discussedwith respect to FIG. 2.

The proximity regulation system 140 in the illustrated embodiment, is adedicated device that is constructed of special-purpose hardwareemploying a software program, which directs its operation. In analternative embodiment, the proximity regulation system 140 may beintegrated into a power algorithm employing software that controls thepower circuit 130. The proximity regulation system 140 may be installedwhen the portable cell phone 126 is constructed. Alternatively, theproximity regulation system 140 may be an after market addition to thealready constructed portable cell phone 120. In one embodiment, theproximity regulation system 140 may be installed with a switch thatallows the portable cell phone user 150 to disengage the proximityregulation system 140. In another embodiment, the proximity regulationsystem 140 may be used with a personal digital assistant or any otherportable device that may emit radio frequency energy within the vicinityof a user.

The portable cell phone user 150 is typically anyone who uses a portablecell phone. This, of course, includes children through senior adults. Inthe illustrated embodiment, the portable cell phone user 150 is usingthe portable cell phone 120 proximate their head. Alternatively, theportable cell phone user 150 may use the portable cell phone 120 whileattached to a belt clip or in conjunction with a headset. In anotherembodiment, the portable cell phone user 150 may use the portable cellphone 120 for data text messaging. In this case, the portable cell phone120 may be typically located in front of the portable cell phone user150 and within a distance of an arm's length. It is also contemplatedthat the portable cell phone 120 may transmit and receive other forms ofmultimedia communications such as video.

Turning now to FIG. 2, illustrated is a block diagram of an embodimentof a portable cell phone, generally designated 200, employing aproximity regulation system 210 constructed in accordance with theprinciples of the present invention. The portable cell phone 200includes the proximity regulation system 210, a power circuit 240, aheadset operation mode input 250, a belt clip sensor 260 and a datatransfer operation mode circuit 270. The portable cell phone 200 isattached to a belt clip 280 having a position indicator 290. Theproximity regulation system 210 includes a location sensing subsystem220 and a power governing subsystem 230.

The proximity regulation system 210 determines a proximity transmitpower level of the portable cell phone 200 based on the location of theportable cell phone 200 proximate a portable cell phone user. In theillustrated embodiment, the proximity regulation system 210 is adedicated device that is solely hardwired. As discussed above withrespect to FIG. 1, the proximity regulation system 210 is coupled to thepower circuit 240. Additionally, the proximity regulation system 210 iscoupled to the headset operation mode input 250, the belt clip sensor260 and the data transfer operation mode circuit 270. Of course, aportable cell phone may still employ the proximity regulation system 210without the headset operation mode input 250, the belt clip sensor 260or the data transfer operation mode circuit 270.

The location sensing subsystem 220 is coupled to the power governingsubsystem 230, and determines a location of the portable cell phone 200proximate a user. In the illustrated embodiment, the location sensingsubsystem 220 is embodied in an integrated circuit. In anotherembodiment, the location sensing subsystem 220 may be embodied as asequence of operating instructions.

In an exemplary embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is proximate the head of theuser if there is no indication that the portable cell phone 200 is in adata transfer operation mode, a headset operation mode or located on abelt clip. In another embodiment, the location sensing subsystem 220 maydetermine if the portable cell phone 200 is proximate the head of theuser through a designated sensor 225 located on the portable cell phone200.

The designated sensor 225 may be an inductively coupled loop thatchanges a surrounding magnetic field when in the vicinity of the user'shead. The change in the magnetic field creates a change in the inductivecoupling thereby causing an impedance change associated with theinductively coupled loop. The impedance change may affect the currentflow in the inductively coupled loop, which can be used to indicate theproximity of the portable cell phone 200 to the user's head.

In an alternative embodiment, the designated sensor 225 may also be acontact sensor that indicates proximity of the portable cell phone 200to the user's head when the portable cell phone 200 is touching theuser's ear. The contact sensor may also indicate proximity of theportable cell phone 200 to the user by contact from the user's hand. Oneskilled in the pertinent art will understand that other sensors may beused to indicate the proximity of the portable cell phone 200 to theuser's body.

In an alternative embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is proximate the body of theuser when receiving an indication from the data transfer operation modecircuit 270. Additionally, the location sensing subsystem 220 maydetermine that the portable cell phone 200 is proximate the body of theuser if the portable cell phone 200 is located on the belt clip 280 or aheadset is inserted in the headset operation mode input 250. Still,another embodiment may indicate that the portable cell phone 200 is awayfrom the body of the user when the portable cell phone 200 is in acradle.

The power governing subsystem 230 is coupled to the location sensingsubsystem 220. The power governing subsystem 230 determines theproximity transmit power level of the portable cell phone 200 based onthe location of the portable cell phone 200 as determined by thelocation sensing subsystem 220. In one embodiment, the network adjustedtransmit power level may be reduced to a value determined by theproximity transmit power level when the location of the portable cellphone 200 is within the vicinity of the user's head. In anotherembodiment, the network adjusted transmit power level may be similarlyreduced when the location of the portable cell phone 200 is just withinthe vicinity of a user's body.

In another embodiment, the proximity transmit power level may match thenetwork adjusted transmit power level, which may be the maximum transmitpower level of, for instance, one watt, when the portable cell phone 200is operating in the headset operation mode or the data transfer mode. Instill another embodiment, the proximity transmit power level may befurther reduced when the portable cell phone user is a child. A switch235 may be installed on the portable cell phone 200 to allow this useroption. Additionally, the switch 235 may also allow the user todisengage the proximity regulation system 210 whenever desired. In oneembodiment, the switch 235 may be a standard software switch that theuser controls through a display and a keypad of the portable cell phone200.

The headset operation mode input 250 is a conventional receptacle forreceiving a headset that allows hands-free operation. As mentionedabove, the headset operation mode input 250 is coupled to the proximityregulation system 210. The location sensing subsystem 220 of theproximity regulation system 210 receives an indication that the headsetis in use from the headset operation mode input 250 when a headset isinserted. In one embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is not within the vicinityof the head of the user upon receiving indication from the headsetoperation mode input 250.

In another embodiment, the location sensing subsystem 220 may determinethat the portable cell phone 200 is within the vicinity of the user'sbody if the headset is inserted in the headset operation mode input 250.In an alternative embodiment, the location sensing subsystem 220 maydetermine that the headset operation mode input 250 may be used inconjunction with the belt clip sensor 260 to indicate that the portablecell phone 200 is proximate the user's body.

The belt clip sensor 260 is coupled to the proximity regulation system210 and indicates when the portable cell phone 200 is located within thebelt clip 280. The belt clip sensor 260 may be a contact sensor that isdepressed by a protrusion on the belt clip 280 when placed in the beltclip 280. In an alternative embodiment, the belt clip sensor 260 may usean inductively coupled loop constructed to indicate to the locationsensing subsystem 220 that the portable cell phone 200 is in the beltclip 280.

The data transfer operation mode circuit 270 is coupled to the proximityregulation system 210 and indicates to the location sensing subsystem220 of the proximity regulation system 210 when the portable cell phone200 is being used for data text messaging. As mentioned above withrespect to the discussion of the antenna 125 of FIG. 1, the data textmessaging may be received from a communications network via an antennasuch as those shown in FIG. 1.

The belt clip 280 is a conventional device for holding the portable cellphone 200. The belt clip 280 is typically constructed of plastic andconstructed to attach to a user's belt. The belt clip 280 may hold theportable cell phone 200 when the user is not using the portable cellphone 200. In alternative embodiments, the belt clip 280 may hold theportable cell phone 200 when the headset is being employed. In otherembodiments, another type of clip may be used by the user to hold theportable cell phone 200. For example, instead of the belt clip 280, theuser may store the portable cell phone 200 in a clip that attaches to ashirt pocket or an arm band.

The position indicator 290 of the belt clip 280 may be a protrusion thatdepresses the belt clip sensor 260 on the portable cell phone 200 toindicate to the location sensing subsystem 220 that the portable cellphone 200 is positioned in the belt clip 280. In an alternativeembodiment, the position indicator 290 may be a metallic insert thatvaries the magnetic field of an inductively coupled loop of the beltclip sensor 260. It should be noted that other pertinent components notshown may be included within the portable cell phone 200 withoutdeparting from the scope of the present invention.

Turning now to FIG. 3, illustrated is a flow diagram of an embodiment ofa method, generally designated 300, of operating a portable cell phoneconstructed in accordance with the principles of the present invention.The method 300 starts in a step 305 with an intent to operate a portablecell phone.

Following the step 305, the portable cell phone determines its locationproximate a user in a step 310. In one embodiment, the location may bedetermined by a designated sensor that indicates the proximity of theportable cell phone to a user's head. In alternative embodiments, thelocation may be determined by other sensors including a belt clipsensor, a cradle sensor, or a headset sensor.

After determining proximity to the user, the portable cell phoneprovides a control signal in a step 320. The control signal may, forinstance, be either a voltage level or current level that is designatedto correspond to the previously determined location. Those skilled inthe pertinent art will understand the use of control signals torepresent a determined condition.

After providing a control signal, the portable cell phone determines ifthe control signal indicates proximity of the portable cell phone to theuser in a first decisional step 330. In one embodiment, various controlsignals may be designated to correspond to different locations of theportable cell phone proximate the portable cell phone user. For example,one control signal may represent that the portable cell phone is in thevicinity of the user's head. Another control signal may be used torepresent that the portable cell phone is in the vicinity of the user'sbody. In alternative embodiments, the control signal may represent thatthe portable cell phone is not within the vicinity of the user's body.

In the illustrated embodiment, if it is determined that the portablecell phone is proximate the user, then the transmit power level isreduced as determined by a value of a proximity transmit power level, ina step 340. In one embodiment, the transmit power level may be reducedto one network adjusted transmit power level whenever the portable cellphone is within the vicinity of any part of the user's body. In anotherembodiment, the transmit power level may be reduced to various allowableproximity transmit power levels depending on the vicinity of theportable cell phone to different parts of the user's body.

After adjusting the transmit power level, the portable cell phone thentransmits at a reduced level in a step 350. In one embodiment, theadjusted transmit power level may not exceed the network adjustedtransmit power level as determined by the communications path betweenthe portable cell phone and the communications tower. In otherembodiments, the adjusted transmit power level may be reduced to theproximity transmit power level. Finally, the transmission of theportable cell phone ends in a step 370.

Returning now to the first decisional step 330, if the portable cellphone is not proximate the user, then the method 300 proceeds to a step360 wherein the portable cell phone transmits at the network adjustedtransmit power level. In one embodiment, the network adjusted transmitpower level may equal the maximum transmit power level of a portablecell phone. In other embodiments, the network adjusted transmit powerlevel may be a reduction from the maximum transmit power level due tothe communications path between the communications tower and theportable cell phone. After transmitting in step 370, the method 300 endsin the previously mentioned step 360.

Although the present invention has been described in detail, thoseskilled in the art should understand that they can make various changes,substitutions and alterations herein without departing from the spiritand scope of the invention in its broadest form.

1. A proximity regulation system for use with a portable cell phone,comprising: a location sensing subsystem configured to determine alocation of said portable cell phone proximate a user by determining amode of operation of said portable cell phone; and a power governingsubsystem, coupled to said location sensing subsystem, configured todetermine a proximity transmit power level of said portable cell phonebased on said location.
 2. The proximity regulation system as recited inclaim 1 wherein said proximity transmit power level is reduced when saidlocation is within a vicinity of a user's head.
 3. The proximityregulation system as recited in claim 1 wherein said proximity transmitpower level is limited to a predetermined maximum level.
 4. Theproximity regulation system as recited in claim 1 wherein said proximitytransmit power level is maximum when said portable cell phone isoperating in a headset operation mode or a data transfer operation mode.5. The proximity regulation system as recited in claim 1 wherein saidportable cell phone is held in a clip associated with said user.
 6. Theproximity regulation system as recited in claim 1 wherein said locationsensing subsystem or said power governing subsystem is embodied in anintegrated circuit.
 7. The proximity regulation system as recited inclaim 1 wherein said location sensing subsystem or said power governingsubsystem is embodied in a sequence of operating instructions.
 8. Theproximity regulation system as recited in claim 1 wherein said locationsensing subsystem is further configured to determine said location byemploying a sensor of said portable cell phone.
 9. The proximityregulation system as recited in claim 8 wherein said sensor is selectedfrom the group consisting of: a designated sensor employing changes in asurrounding magnetic field, a contact sensor, a clip sensor, and acradle sensor.
 10. A method of operating a portable cell phone,comprising: determining a location of said portable cell phone proximatea user based on a mode of operation of said portable cell phone;providing a control signal based on said location; and determining aproximity transmit power level of said portable cell phone based on saidcontrol signal.
 11. The method as recited in claim 10 wherein saidproximity transmit power level is reduced when said location is within avicinity of a user's head.
 12. The method as recited in claim 10 whereinsaid proximity transmit power level is limited to a predeterminedmaximum level.
 13. The method as recited in claim 10 wherein saidproximity transmit power level is maximum when said portable cell phoneis operating in a headset operation mode or a data transfer operationmode.
 14. The method as recited in claim 10 wherein said portable cellphone is held in a clip associated with said user.
 15. The method asrecited in claim 10 wherein said determining said location is performedby a location sensing subsystem embodied in an integrated circuit. 16.The method as recited in claim 10 wherein said determining a proximitytransmit power level is performed by a power governing subsystemembodied in a sequence of operating instructions.
 17. The method asrecited in claim 10 further comprising determining said locationemploying a sensor of said portable cell phone.
 18. The method asrecited in claim 17 wherein said sensor is selected from the groupconsisting of: a designated sensor employing changes in a surroundingmagnetic field, a contact sensor, a clip sensor, and a cradle sensor.19. A portable cell phone, comprising: an operation mode input orcircuit; and means for determining a transmit power level of saidportable cell phone based on said operation mode input or circuit. 20.The portable cell phone as recited in claim 19 wherein said operationmode input or circuit is selected from the group consisting of: aheadset operation mode input, and a data transfer operation modecircuit.
 21. A proximity regulation system for use with a portable cellphone, comprising: a power governing subsystem configured to determine atransmit power level of said portable cell phone based on a mode ofoperation thereof.
 22. The proximity regulation system as recited inclaim 21 wherein said mode of operation is selected from the groupconsisting of: a headset operation mode, and a data transfer operationmode.
 23. The proximity regulation system as recited in claim 21 whereinsaid transmit power level is maximum when said portable cell phone isoperating in a headset operation mode or a data transfer operation mode.24. A proximity regulation system for use with a portable cell phone,comprising: means for determining a transmit power level of saidportable cell phone based on a mode of operation thereof.
 25. Theproximity regulation system as recited in claim 24 wherein said transmitpower level is limited to a predetermined maximum level.
 26. Theproximity regulation system as recited in claim 24 wherein said transmitpower level is maximum when said portable cell phone is operating in aheadset operation mode or a data transfer operation mode.
 27. Theproximity regulation system as recited in claim 24 wherein said mode ofoperation is selected from the group consisting of: a headset operationmode, and a data transfer operation mode.